Supporting structure of a bag packaging machine

ABSTRACT

The invention relates to a supporting structure of a bag packaging machine for the vertical forming, filling, and sealing of tubular bags.  
     Conventional structures of this type of machine comprise a housing or a three-dimensional framework in which the various assemblies of the machine are arranged in accordance with fixed coordinates.  
     The object of the present invention is to propose a supporting structure that permits the free assignment of the assemblies and thus ensures a design simplification of both the manufacture and the fitting. This object is achieved in that the supporting structure comprises a horizontal floor framework ( 1 ), two supporting pillars ( 5 ) and a crossbar ( 7 ), wit the individual assemblies being fixed to the supporting pillars ( 5 ) such that their height can be adjusted. Thus, the coordinates of the assemblies can be adapted optimally to the intended use of the machine, in particular to the bag size.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority under 35 U.S.C. § 119 of Swiss Patent Application No. 2000 1291/00, filed on Jun. 30, 2000, the disclosure of which is expressly incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a supporting structure for a bag packaging machine for the vertical forming, filling, and sealing of tubular bags to which individual assemblies of the machine are attached.

[0004] 2. Discussion of Background Information

[0005] Such assemblies are mainly the film web feed with film roll and guide and transport rolls, the so-called size unit having a filling tube for filling the product into the bag to be produced from a flexible film web, and having a form shoulder over which the film web is drawn in order to form it into a tube, a longitudinal sealing device in order to produce the longitudinal seam of the bag, and a transverse sealing device in order to produce the transverse seam, i.e., to seal the bag.

[0006] In the bag packaging machines known in practice and in the patent literature (see, e.g., DE C 303 13 99), these assemblies are accommodated and fixed in a housing or three-dimensional framework. The placement of the individual assemblies in the housing or in the framework is determined according to fixed assignment points (also called “coordinates” in technical terminology), since the structure and the three- dimensional framework do not permit the assemblies to be mutually arranged freely.

[0007] This results from the fact that the known structures are designed from the outset for quite specific dimensions of the bags to be produced, where each assembly must occupy a specific position. Thus, the supporting elements in the housing or framework are provided in accordance with the size of the bag, and adaptation of a housing usually comprising side-walls and a front plate, as well as of a framework comprising many bars and plates, to other bag sizes proves to be extremely difficult. Thus, in the prior art, virtually the only machines known are those designed individually for each size (or, in the most favorable case, for very small size variations). This is a severe disadvantage, both for the manufacturer of the bag packaging machine, who must have an entire series of machine types in his range and thus can not manufacture these machines efficiently, and for the user of the machine, who is virtually unable to adapt the length of the bag to market requirements.

SUMMARY OF THE INVENTION

[0008] The object of the present invention is to overcome these disadvantages of the prior art and to propose the design of a bag packaging machine that, starting from a novel supporting structure, permits the free assignment of the individual assemblies in the machine and thus a considerable design simplification of both the manufacture and the fitting of the machine. Furthermore, the invention is intended to make it possible to adapt thoroughly to customers' wishes, i.e., to enable a free choice of the size range of the machine.

[0009] All these objectives are achieved with a supporting structure of a generic bag packaging machine according to the characterizing features of claim 1. A great variety of sizes can be produced on the same machine in that at least a part of the individual assemblies of the machine—preferably the longitudinal sealing device and the transverse sealing device—are fixed on the vertical guide of the supporting pillars such that their height can be adjusted. The ease with which the height of the assemblies can be adjusted, which is a direct consequence of the very simple type of construction of the supporting structure, is the crucial feature of the invention. An additional advantage of the design of the invention lies in the machine, thanks to the fact that there are no walls and plates in the structure, being extremely transparent, so that all the working parts can be observed from outside during operation, thus making it possible to intervene immediately if something is not in order. However, the machine must of course be equipped with the legally required protective devices for the avoidance of accidents, which is achieved in the most favorable case by means of a transparent casing.

[0010] The invention shall now be described in greater detail on the basis of some illustrated exemplary embodiments, with further advantages to be described in the course of the description.

[0011] Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:

[0013]FIGS. 1a and 1 b show a front or side view of the “naked” supporting structure of the invention, i.e., the supporting structure before the working parts of the machine that are installed together as an assembly, are fitted;

[0014]FIGS. 2a and 2 b show the same views as FIGS. 1a and 1 b with an assembly, namely the longitudinal sealing device, fixed to the supporting structure;

[0015]FIG. 2c is the floor plan of a part of FIGS. 2a and 2 b;

[0016]FIGS. 3a and 3 b show the same views as FIGS. 2a and 2 b with an additional assembly, namely the transverse sealing device, fixed to the supporting structure;

[0017]FIG. 4a shows a side view according to the views of FIGS. 1b, 2 b, and 3 b, in which another additional assembly, namely the film feed device, is visible, although in a state where it is not yet fixed to the structure;

[0018]FIGS. 5a and 5 b show the finished fitted bag packaging machine in views corresponding to those of FIGS. 1 to 4 a, partly in a simplified representation.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0019] The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.

[0020] In FIGS. 1a and 1 b, which show the supporting structure of the invention in its basic elements, a horizontal floor framework designated as 1 and formed from two crossbeams 2 and a connecting support 3, is shown. The floor framework is equipped with four bracing feet 4 that allow a perfect leveling of the framework 1 and thus of the entire machine. The embodiment of the framework shown here is, of course, to be considered purely as an example of a floor framework. It could also comprise, e.g., four beams forming a square or of a full plate.

[0021] A vertical supporting pillar 5 is fixed approximately in the middle of each crossbeam 2. Moreover a guide 6 is fixed to each supporting pillar 5, preferably, but not necessarily, in the vertical plane defined by the axis of symmetry of the pillars 5 and facing the inside of the structure 1.

[0022] The upper ends of the supporting pillars 5 are rigidly connected by a horizontal crossbar 7, so that a rigid supporting structure is formed from the floor framework 1, the supporting pillars 5, and the crossbar 7. Two horizontal supporting arms 8, which can have, e.g., the form of round bolts, are also fixed in the upper crossbar 7, as can be seen in FIGS. 1a and 1 b. These supporting arms are provided for a preferred variant embodiment of the invention, and their function will be explained later. The invention can also be implemented without such supporting arms.

[0023] The invention now provides for at least a part of the individual assemblies of the machine, e.g., at least one assembly, to be fixed to the vertical guide 6 of the supporting pillar 5 such that its height can be adjusted. This situation is shown in FIGS. 2a and 2 b, where the longitudinal sealing device 9 is shown mounted on the supporting structure. Without desiring to go into the design details of such a device, since they are not the subject of this invention, we wish to establish that this device comprises a rigid support 10 on which the horizontal guides 11 and 12 for the sealing tools 13 and 14 are supported. The tool 14 is a heated, vertical plate, while the tool 13 is a so-called filling tube pressure device in the form of a roll. The function of such a longitudinal sealing device is known to all those skilled in the art: by pressing the longitudinal seam of the bag (not shown) against the filling tube 15 (only shown in section in FIG. 2c), and under the action of heat, the plastic material of the film is softened and the seam is formed. The flat film is thus shaped to produce a closed tube, in accordance with the known technology of bag formation.

[0024] Simply the fact that the support 10 is supported in the guides 6 on both sides such that its height can be adjusted, is crucial for the present invention. For this purpose, and according to a preferred variant embodiment of the invention, both guides 6 are constructed as a gear rack. A horizontal axle 16, which is driven in the center by a motor 17 and carries a pinion 18 on each side, is fixed to the support 10. Each pinion engages with the gear rack of the corresponding guide 6. With this system, the support 10, and thus the entire longitudinal sealing device, can be displaced upward and downward along the guides 6 by motor.

[0025] This type of movement of the longitudinal sealing device is, of course, not the only one that can be used within the context of this invention. In the simplest embodiment of the invention (not shown), it can be provided, for example, that the (at least) one assembly can be fixed and its height can be adjusted along the vertical guide 6 manually, i.e., not motorized. In such a case, the support 10 could have one guide sleeve each per side (not shown) that slides on the guides 6. The sleeves can then be blocked on the guides 6, e.g., by clamps. The control box of the machine is also indicated in FIG. 2a by 19.

[0026] According to a preferred variant embodiment of the invention, which is shown in FIGS. 2a and 2 c and has already been described, it is provided for at least one of the height-adjustable assemblies, such as, e.g., the longitudinal sealing device to be s equipped with its own drive device for the mechanized movement along the vertical guides 6. Simply the fact that the coordinates of the assembly, i.e., their mutual height position in the supporting structure, the intended use of the machine, and in particular of course the size of the bag, can be adapted without changing anything on the supporting structure, is crucial for the invention. This gives the manufacturer of the machine great flexibility, since he can meet very broad customer needs with a single type of machine. A reduction in the number of machine types yields additional financial advantages, thanks to the possibilities for greater efficiency in manufacture. The user of the machine also gains flexibility, however, since he is put in the position of being able to change the bag size with the same machine rapidly and without high costs—an advantage that is highly prized by customers.

[0027] According to a preferred variant embodiment of the invention, it is furthermore provided, in particular, for the longitudinal sealing device assembly (as shown in FIGS. 2a and 2 c) and the transverse sealing device assembly to be fixed on the vertical guides 6 of the supporting pillars 5 such that their height can be adjusted. This embodiment is shown in FIGS. 3a and 3 b, which differ from FIGS. 2a and 2 c only in that here a likewise height-adjustable transverse sealing device 20 is conducted on the same vertical guides 6 as the longitudinal sealing device 9 already described.

[0028] In its construction and its seating on the guides 6, this sealing device is very similar to the longitudinal sealing device already described: it differs from the latter only in that it has two identical horizontal sealing tools 21 and 22 facing one another that, for forming the transverse seam of the bag, are brought closer on both sides of the packaging tube made of film, until they virtually touch each other. The transverse sealing device is placed under the filling tube 15, of course (FIG. 2c). This device 20 also has a motor 23 and a horizontal axle 24 that has on both sides a pinion 25 engaged with the gear rack of the corresponding guide 6.

[0029] According to another preferred variant embodiment of the invention, not shown in the figures, it is provided for the motorized drive device for the height-adjustable assemblies (e.g., 9 and 20 of the above-mentioned FIGS. 2 and 3) to be pneumatic or hydraulic and for it to have at least one cylinder/piston unit (not shown). This is a particularly simple and cost-effective solution that can be sufficient to satisfy the objective in many cases. For a so-called continuous operation of the machine, i.e., an operation in which the film is transported continuously and the longitudinal sealing device must therefore perform an alternating upward and downward motion in the rhythm of the bag production, however, the solution with the gear rack is more favorable, since it allows faster movements. Another measure for facilitating the upward and downward movement of the assembly is a balancing of the masses, whether by attaching weights or by mechanical springs, pneumatic cushioning, etc. Such solutions for balancing the masses are known to all those skilled in the art and therefore do not need to be described here in greater detail. We wish to emphasize, however, that these measures only become important in the context of continuous operation of the machine. For the simple height adjustment of the assemblies, i.e., for the main object of the invention, such a balancing of the masses is not necessary.

[0030] According to another preferred embodiment of the invention, it is provided that two horizontal support arms 8 are fixed to the crossbar 7 at a mutual distance. The entire size unit 26 (FIG. 5b) is then mounted on these supporting arms 8, as can be seen from FIGS. 4a and 5 b. The size unit 26 is an assembly and essentially comprises the filling tube 15 with funnel tube 27, the form shoulder 28, and the film removal belts 29 with the motor 30. The form shoulder 28 serves to convert the film from a flat structure to a tube. The entire assembly of the size unit 26 is pushed onto the supporting arms 8 and fixed thereon. This assembly is therefore in a fixed position in the area, while the assemblies of the longitudinal sealing device 9 and/or the transverse sealing device 20 are attached to the supporting pillars 5 such that their height can be adjusted.

[0031] According to another preferred variant embodiment of the invention, it is provided for the two supporting pillars 5 to define a vertical plane E-E (FIG. 4a) that intersects the floor framework 1 along a central axis. In order to achieve a good weight distribution in the machine, it is provided for the bag-forming, filling, and sealing component parts 26; 15; 9; 20 of the machine to lie in front of this plane E-E, while the film-guiding component parts with the film roll 31, film roll holder 32, dancer arm 33, film drive 34, and supporting plates 35 lie behind this plane. Thanks to this solution, the center of gravity of the machine can be brought close to the vertical plane E-E, with it of course being necessary to take into consideration the fact that the weight of the film roll 31 drops as the roll is used up, so that a certain shift in the center of gravity of the machine is unavoidable. This shift is less serious, the closer the center of gravity of the machine lies to the central plane E-E from the outset. This is the object of this particular variant embodiment of the invention.

[0032] Furthermore it is provided according to another preferred variant for the supporting pillars 5 and/or the horizontal crossbar 7 and/or the connecting bar 3 to also be used as a channel for the electric cables, motor cables, control elements, pneumatic or hydraulic elements (all not shown). The advantages of such a solution, which is made possible by the fact that the components of the floor framework 1 can be hollow profiles, are obvious.

[0033] The solutions shown in FIGS. 1-5 are to be viewed as exemplary embodiments, of course. Other variants are conceivable without departing from the scope of the invention. Thus, e.g., the entire size unit 26 could also be fixed to the supporting structure such that its height can be adjusted, in order to create a further adjustment possibility. Moreover, it can be provided for the supporting structure to also be used as a support for the weighing machine (not shown) normally situated above the funnel tube 27. In this case, it can advantageously be provided for the supporting pillars 5 to extend farther upwards above the crossbar 7.

[0034] It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

[0035] Description of the Figures 1 Floor framework 2 Crossbeam 3 Connecting bar 4 Bracing feet 5 Supporting pillar 6 Vertical guide 7 Crossbar 8 Supporting arm 9 Longitudinal sealing device 10 Support 11 Horizontal guide 12 Horizontal guide 13 Sealing tool 14 Sealing tool 15 Filling tube 16 Axle 17 Motor 18 Pinion 19 Control box 20 Transverse sealing device 21 Sealing tool 22 Sealing tool 23 Motor 24 Axle 25 Pinion 26 Size unit 27 Funnel tube 28 Form shoulder 29 Film removal belt 30 Motor 31 Film roll 32 Film roll holder 33 Dancer arm 34 Film drive 35 Supporting plate 

What is claimed:
 1. Supporting structure of a bag packaging machine for the vertical forming, filling, and sealing of tubular bags to which individual assemblies of the machine are attached, characterized in that the supporting structure includes the following basic elements: a horizontal floor framework (1) two vertical supporting pillars (5) fixed on the floor framework, with a vertical guide (6) being provided on each supporting pillar (5), a horizontal crossbar (7) rigidly connecting the upper ends of the supporting pillar (5) and in that at least a part of the individual assemblies is/are fixed to the vertical guides (6) of the supporting pillars (5) so that its/their height can be adjusted, such that the coordinates of the assemblies can be adapted to the intended use, in particular the bag length, without changes to the supporting structure.
 2. Supporting structure of a bag packaging machine according to claim 1, characterized in that the following assemblies are fixed on the vertical guides (6) of the supporting pillars (5) such that their height can be adjusted: the longitudinal sealing device (9) for forming the vertical longitudinal seam of the bag and/or the transverse sealing device (20) for forming the horizontal transverse seam of the bag.
 3. Supporting structure of a bag packaging machine according to claim 1, characterized in that at least one of the height-adjustable assemblies is equipped with its own drive device for its mechanical movement along the vertical guides (6).
 4. Supporting structure of a bag packaging machine according to claim 3, characterized in that the drive device is pneumatic or hydraulic and contains at least one cylinder/piston unit.
 5. Supporting structure of a bag packaging machine according to claim 3, characterized in that the drive device contains at least one electric motor (17; 23).
 6. Supporting structure of a bag packaging machine according to claim 1, characterized in that the vertical guides (6) of the supporting pillars (5) are designed as gear racks and that the height-adjustable assemblies can be moved upward and downward by means of a motorized pinion (18) on each guide (6).
 7. Supporting structure of a bag packaging machine according to claim 1, characterized in that two horizontal arms (8) are fixed on the horizontal crossbar (7) at a mutual distance and in that the size unit (26) with the filling tube (15) is mounted on these supporting arms (8).
 8. Supporting structure of a bag packaging machine according to claim 1, characterized in that the two supporting pillars (5) define a vertical plane (E-E) that intersects the floor framework (1) along a central axis and that the bag-forming, filling, and sealing component parts (26; 15; 9; 20) of the machine lie in front of this plane (E-E), while the film-feeding component parts (32; 33; 34; 35) with the film roll (31) lie behind this plane (E-E).
 9. Supporting structure of a bag packaging machine according to claim 1, characterized in that the supporting pillars (5) and/or the horizontal crossbar (7) and/or the connecting bar (3) can also be used as a channel for the electric cables, motor cables, control elements, pneumatic or hydraulic elements. 